Underwater postbox is a distinctive dive site located 30 metres from the shore of Green Island, Taiwan. The site features an artificial reef structure at an average depth of 9 metres, with a total depth range between 5 and 11 metres. Divers can access the site via shore or boat. Conditions vary, with visibility ranging from 15 to 40 metres and moderate currents. The site is suitable for beginners and supports night diving. Facilities available nearby include air fills, equipment rental, showers, and changing rooms. Divers should be aware of potential hazards including boat traffic, surf, and sharp coral.

Clownfish Island is a reef site located off Green Island, Taiwan. The site offers depths typically ranging between 12 and 15 metres, with an average depth of 13 metres. Divers can expect mild currents and visibility generally between 20 and 30 metres. Entry to the water is possible from both shore and boat. The site is suitable for intermediate divers. Water temperatures fluctuate throughout the year, ranging from 25C in the winter months to 30C in July. Divers should be aware of sharp coral present in the area.

Shilang is a reef site located off Green Island, Taiwan, near the town of Shih-Lang. The site features a sandy bottom at 11 metres, where a steel structure housing an underwater mailbox and a heart-shaped sculpture are located. Divers can access the site via shore or boat entry. Depths typically range between 10 and 18 metres, with an average depth of 10 metres. Visibility is variable, ranging from 10 to 40 metres, and currents are generally moderate. The site is suitable for beginner divers. Hazards include jellyfish, sharp coral, and stonefish.

Electric Pole Reef at Green Island features a unique combination of natural reef and an artificial structure built around a submerged wire pole. The site reaches depths of 16 to 25 metres, with an average of 23 metres, making it accessible for beginner divers. Visibility typically ranges from 10 to 30 metres, and currents are generally mild. Divers can encounter wrasses, which are very common, alongside uncommon species such as spotfin lionfish, regal angelfish, and various nudibranchs. Boat access is required to reach the site. Divers should exercise caution regarding sharp coral and rocks, and be aware of sea urchins on the seabed.

Zhongliao Port on Green Island, Taiwan, offers a shallow reef and muck diving environment suitable for beginners. Divers typically experience depths of 5 metres with mild currents and visibility ranging from 10 to 30 metres. Shore entry is standard for this site. Marine life recorded here includes wrasses, Indian lionfish, snowflake moray, and various nudibranchs such as Nembrotha and Trance Wrinkle Dorid. Other species observed include Ijima's sea snake, semicircle angelfish, striped surgeonfish, banded coral shrimp, porcupinefish, white-spotted puffer, and yellow boxfish. Hazards to consider include potential entanglement, variable visibility, and surf conditions. Typical dives last approximately 40 minutes.

Crocodile Reef is located on the outer edge of the Green Island reef system, featuring a wall and slope that descends from 18 to 31 metres. This site is suited for advanced divers due to strong currents and depths that require careful management of nitrogen narcosis and decompression limits. Visibility is variable, ranging from 10 to 40 metres. Access is by boat only, and divers should plan their profiles around slack water to manage the current. Water temperatures remain between 25 and 29 degrees Celsius throughout the year. Night diving is available, though coordination with boat operators is necessary due to local vessel traffic.

Jichang Fault is a dramatic underwater landscape situated on the outer edge of the Green Island reef system. This site is defined by its geological fault line, which has created a complex topography of walls, canyons, and drop-offs reaching depths of 46 metres. With an average depth of 30 metres, this site is suited for advanced divers. Visibility ranges from 15 to 40 metres, allowing for clear views of the structural features. Strong currents are a constant factor, requiring drift-diving experience and precise buoyancy control. Access is by boat only, and divers should time their entry to coincide with slack water to safely explore the deeper sections.

Steel Reef is an artificial reef structure located 500 metres off the coast of Green Island, Taiwan. This site is accessible only by boat and is suited for intermediate divers and snorkellers. The reef sits at a consistent depth of 12 metres. Conditions at the site are variable, with visibility ranging from 10 to 25 metres and moderate currents. Divers should be aware of potential hazards including surge, jellyfish, stonefish, and sharp coral. Typical dives at this location last approximately 45 minutes. Water temperatures remain warm throughout the year, fluctuating between 25 and 30 degrees Celsius.